package com.mercury.ec.framework.air.core.client.impl.skyecho.util;

import java.security.KeyFactory;
import java.security.PrivateKey;
import java.security.PublicKey;
import java.security.spec.PKCS8EncodedKeySpec;
import java.security.spec.X509EncodedKeySpec;

/**
 * RSA签名验签类
 * @author yangql
 * @date Jan 18, 2021
 */
public class RSASignature {
    /**
     * 签名算法
     */
    public static final String SIGN_ALGORITHMS = "SHA1WithRSA";

    /**
    * RSA签名
    * @param content 待签名数据
    * @param privateKey 商户私钥
    * @param encode 字符集编码
    * @return 签名值
    */
    public static String sign(String content, String privateKey, String encode)
    {
        try
        {
            PKCS8EncodedKeySpec priPKCS8    = new PKCS8EncodedKeySpec( b64decode(privateKey) );

            KeyFactory keyf                 = KeyFactory.getInstance("RSA");
            PrivateKey priKey               = keyf.generatePrivate(priPKCS8);

            java.security.Signature signature = java.security.Signature.getInstance(SIGN_ALGORITHMS);

            signature.initSign(priKey);
            signature.update( content.getBytes(encode));

            byte[] signed = signature.sign();

            return b64encode(signed);
        }
        catch (Exception e)
        {
            e.printStackTrace();
        }

        return null;
    }

    public static String sign(String content, String privateKey)
    {
        try
        {
            PKCS8EncodedKeySpec priPKCS8    = new PKCS8EncodedKeySpec( b64decode(privateKey) );
            KeyFactory keyf = KeyFactory.getInstance("RSA");
            PrivateKey priKey = keyf.generatePrivate(priPKCS8);
            java.security.Signature signature = java.security.Signature.getInstance(SIGN_ALGORITHMS);
            signature.initSign(priKey);
            signature.update( content.getBytes());
            byte[] signed = signature.sign();
            return b64encode(signed);
        }
        catch (Exception e)
        {
            e.printStackTrace();
        }
        return null;
    }

    /**
    * RSA验签名检查
    * @param content 待签名数据
    * @param sign 签名值
    * @param publicKey 分配给开发商公钥
    * @param encode 字符集编码
    * @return 布尔值
    */
    public static boolean doCheck(String content, String sign, String publicKey,String encode)
    {
        try
        {
            KeyFactory keyFactory = KeyFactory.getInstance("RSA");
            byte[] encodedKey = b64decode(publicKey);
            PublicKey pubKey = keyFactory.generatePublic(new X509EncodedKeySpec(encodedKey));


            java.security.Signature signature = java.security.Signature
            .getInstance(SIGN_ALGORITHMS);

            signature.initVerify(pubKey);
            signature.update( content.getBytes(encode) );

            boolean bverify = signature.verify( b64decode(sign) );
            return bverify;

        }
        catch (Exception e)
        {
            e.printStackTrace();
        }

        return false;
    }

    public static boolean doCheck(String content, String sign, String publicKey)
    {
        try
        {
            KeyFactory keyFactory = KeyFactory.getInstance("RSA");
            byte[] encodedKey = b64decode(publicKey);
            PublicKey pubKey = keyFactory.generatePublic(new X509EncodedKeySpec(encodedKey));


            java.security.Signature signature = java.security.Signature
            .getInstance(SIGN_ALGORITHMS);

            signature.initVerify(pubKey);
            signature.update( content.getBytes() );

            boolean bverify = signature.verify( b64decode(sign) );
            return bverify;

        }
        catch (Exception e)
        {
            e.printStackTrace();
        }

        return false;
    }
    private static String b64encode(byte[] data) {

		String b64str = new String(Base64.encode(data));
		return b64str;
	}

	private static byte[] b64decode(String data) {
		byte[] decodeData = Base64.decode(data);
		return decodeData;
	}
}

